Highlighting text while reading your book offline works the same as working online. To learn how to highlight text, view Highlighting text in an eTextbook.
IMPORTANT: Please note that all highlights created online with the Reader will be preserved when a book is checked out for offline use or in classic mode. When you go back online, you will see a message asking if you would like to sync your notes and highlights. Confirm that you would like to sync notes and highlights in order to save your notes and highlights to the online version of your eTextbook.